1. Field of the Invention
The present invention relates to a cooling accessory for an electronic component, and more particularly to a heat sink for a memory which can partially seal the internal convective space, so as to control the direction in which the heat is conducted out by the air.
2. Description of the Prior Art
During the recent electronic times, various electronic products have been rapidly developed on the market. In the design of the electronic product, the heat dissipation is the most important, because no matter how excellent the function of a product is, if the device is often burned due to bad heat-dissipating effect, the product will become unuseful. Thereby, various heat sinks have been continuously being developed one after another.
As known from the computer memory, the conventional heat sink is only disposed with two copper sheets at both sides thereof. Due to the fine heat conductivity of the copper, the heat of the memory can be quickly conducted into the air by the two copper sheets. However, the heat dissipating effect reached by the heat exchange between mediums is not fine. The air is the medium with poor heat conductivity, so the heat-dissipating effect of the heat conduction is quite unsatisfied.
Referring to FIGS. 1-2, a heat sink for a memory module disclosed in Taiwan Pat. No. 095219174 comprises two heat-conducting sheets 10 and a fan 20. The two heat conducting sheets 10 is positioned against both sides of a memory A opposite each other, and each heat conducting sheet 10 is formed with an air passage 11. Each air passage 11 includes an entry 111 and an exit 112. The fan 20 is disposed at one end of the two heat conducting sheets 10 and located at the entries 111 of the two air passages 11. The air is blew into the respective air passages 11 by the fan 20, so that the air flows through the respective air passages 11 to discharge the heat of the memory A through convection.
However, the heat-dissipating effect of this heat sink is not fine. Because the fan 20 is disposed at one end of the two heat-conducting sheets 10, and the air is sent from one end of each heat-conducting sheet 10 into the entry 111 of the air passage 11 of each heat-conducting sheet 10, and then the air will be expelled out from the exit 112 of each air passage 11. Hence, the part of the memory A located correspondingly to the entry 111 contacts the lower temperature air, so its heat is easily discharged by the air convection. The part of the memory A located correspondingly to the exit 112 contacts the air which has already absorbed the heat discharged at the entry 111, so the temperature of the air is comparatively higher. Thereby, it is difficult to discharge the heat through convection, thus causing an undesirable heat-dissipating effect of the part of the memory A located correspondingly to the exit 112, different heat-dissipating effects at both ends of the heat-conducting sheets 10 and a higher damage possibility.
The present invention has arisen to mitigate and/or obviate the afore-described disadvantages.